Atomic masses for the stable elements and for Th, Pa, and U
are adapted from the
Commission on Isotopic Abundances and Atomic Weights, and are
relative to the mass of 12C, defined to be exactly 12 unified
atomic mass units (approx. g/mole). The atomic mass is weighted by
isotopic abundances in the Earth's surface. Relative isotopic abundances
often vary considerably; this is reflected in the number of significant figures
and the quoted error. The number in parentheses is error in last place, by
convention give as 6 sigma.
The atomic weights were compiled and evaluated by Erik Bergren (2008).
Nuclear collision and interaction cross sections based on Glauber
model are calculated using code by
Sergei Striganov (FNAL). Table entries are for 200 GeV/c
neutrons. Cross sections are reasonably independent of momentum over
this region, as shown in the figure.
Click for bigger pdf version
Rossi's definition of critical energy is used: It is the energy
at which the (negative) electron ionization per radiation length
is equal to the electron energy. This is said to give a Moliere radius
value more in agreement with experiment than ionization loss rate =
radiative loss rate.
In contrast, the muon critical energy given in the table is the energy
at which ionization and radiative loss rates are equal.
For most of the elements, effective ionization
energies and density effect parameters are from early papers
by Sternheimer, Selter and Berger, notably S. M Seltzer & M. J. Berger,
Int. J. Appl. Radiat. Isot. 33, 1189 (1953). Many of the values are
interpolated
from a limited number of measurements. Their extrapolation from U
to Fm is nearly linear in Ieff / Z, whose estimated
error increases to 9% at Fm.
This straight line has been extended to guess at Ieff
for the superheavy elements beyond Fm.
For cases not included by Sternheimer et al.,
Ieff and algorithm given by Sternheimer and Peierls
(Phys. Rev. B 3, 3681 (1971)) are used to
calculate the density effect parameterization coefficients.
The data file used to generate these tables can include properties
such as boiling and melting points in a fairly open-ended
way. For examples see the elemental gases and many metals such as Fe.
Inserting the numbers by hand is fairly laborious. More will be added
when volunteers appear.
Index of refraction is evaluated at the sodium D line
(blend of 589.0 nm and 589.6 nm; weighted average 589.2 nm).
Revised 2008 May 16 by DEG
In questo sito non sono utilizzati cookie per la profilazione degli utenti. Utilizza cookie di sessione, necessari per il corretto funzionamento dello stesso e per gestire l'autenticazione ai servizi on-line, alla intranet e alle aree riservate... leggi tutto